f-1(x) = (x-7) / 2, you can get this by taking 2x + 7, and doing the opposite operations on x. you also need to go in the reverse direction of Order of Operations. So first, we take 7 away from x, since subtraction is opposite from addition, and it is the last thing we would do in order of operations. next we only have the 2 multiplier left, so we put the x-7 in parenthesis, and divide by 2.